Big Sparking Science Toys · 11:06pm Feb 6th, 2016
Just occasionally something happens which makes me think I love my job! Sadly it has not happened very often of late, but yesterday was a good day. This story began some months ago when I received a forwarded email asking if we could find a home for an orphaned spark chamber from the science museum.
My response was: What!? A spark chamber! From The Science Museum! Yesyesyesyesyesyesyes!
[Explanatory Note for non-particle-detector-nerds]: A spark chamber is a sort of particle detector which was used for research some sixty years ago before they were replaced by more modern instruments. They’re big, awkward to use, tend to break down, and create enormous amounts of electromagnetic interference. They are of no practical value for modern research. But what they lack in utility, they make up for in awesomeness, as they literally show the tracks of particles as sparks.
It consists of a chamber of low pressure gas – usually helium and neon, with a series of metal plates connected to a kilovolt power supply. When a cosmic ray passes through the chamber, it kicks the electrons off the gas molecules, leaving a trail of ions, and then—ZAP! You see a line of bright sparks as the electric current jumps along the low-resistance path between the plates.
There are plenty of YouTube videos showing this, but none of them can really do it justice. This is something you have to see for real.
These days, spark chambers are museum pieces. You can imagine that one built for the London Science Museum—which, from my limited exploration of the cosmos, I will provisionally label as the Most Awesome Place In The Universe—a would be a rather good one.
The offer was if we could repair it and put it on public display, we could have it. Best Deal Ever right?
Sadly for some reason my colleagues in Particle Physics were not so impressed, and were not won over by my fanatical enthusiasm. They dismissed it as too old-fashioned. Some people have no sense of awesomeness. Of course it’s old fashioned, but that’s not the point. If you want to get kids interested in particles, you are far more likely to do it with something that goes bang with lots of sparks, than with a computer display of data. Just as you don’t get them interested in astronomy by showing photos downloaded from some megascope in Hawaii, you do it by taking them out at night and letting them look at the stars through a 6-inch reflector.
But given the lack of enthusiasm from my boss and colleagues, I realised that this wasn’t going to happen. But before giving up I forwarded the email on to a friend outside particle physics just in case she could do something. I wasn’t expecting anything, but, it turned out her boss was much more positive. So I handed it over to them to explore further and negotiate the details. Still assuming that it probably wouldn’t work out—it was all starting to look like it would be too good to be true.
Fast forward two months and I had almost forgotten about it. Then I got a message this week saying she was going out to see it at Wroughton. Would I like to come along?
Wrougton! The science museum storage facility? That place is a legend—at least in the world of British scientific instrument nerds. An old air field in Wiltshire where they store all the stuff they don’t have space for at their London site. Online forums are full of comments complaining about how difficult it is to get access.
Did I want to come along? You bet I did.
So, like Daring Do on the trail of an ancient relic, we ventured out to the far side of Swindon with the retired engineer who had built the thing some years ago. After getting past the security guards we were shown into a huge dark old hangar. Once the lights were on—there it was: a beautiful display piece in black plastic and Perspex, over two metres high, sitting on a palette, among shelf after shelf of old engines, machines, printing presses, looms, turbines, and other treasures which the museum is preserving for future generations.
Some work is clearly needed until it will be sparking again, but this dream is now looking like it might actually happen.
Hooray for the sparky flash box! Glad to hear that this is going much better than expected.
Your colleagues need their nerd licenses checked, they might have expired.
Just a warning. I'm not telling the wife. She would be out at the airport with a credit card buying a ticket before I could blink. (Yes, I married a science nerd far more nerdy than myself. It's wonderful. )
If they managed to get the spark chamber, its a real pity if they havent at least a copy of Frankensteins laboratory, looking after it for the movie studios. After all, you need the HT for the chamber, and even Twilight used a partially enclsed Van De Graaf
If its a modified version of a geiger counter, does it use the electronics for quenching, or does it use halogen quench. would a simple version be pulsed DC due to HT, low current, photographic triggering, or capacitant connected for particle incidence triggering?
What were those scattered patterns? Decaying particles?
Sweeeeet!
Nice! Too bad about the others at your work though. Maybe they just REALLY like computer displays full of data?
3737357
When we get it working I'll send an invite to the party
3737467
I'm guessing you are seeing the result of a particle shower. Somewhere above the detector, a high energy electron interacts with an atom and radiates a photon, which splits into a electron-positron pair, which in turn radiate more photons, and it keeps showering until the energy of the individual particles is below the threshold.
teachers.web.cern.ch/teachers/archiv/hst2000/teaching/expt/muons/casfig11.gif
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That is the problem these days. So many particle physicists just work on software. They dream in C++ and know the Linux kernel like the back of their hand... but give them a soldering iron and you have to point out which is the hot end.
3738460
Wow - so the photon can directly convert to mass?! I've heard of the other way around. This must have been a part of physics I missed (or was sleeping through). Anyway, it's a shame that coolness factor has little bearing on the direction of technology.